In a medium saucepan, combine ½ cup of freshly squeezed lemon juice, ¼ cup of water, and ½ cup of granulated sugar over medium heat. Stir until dissolved, about 3-5 minutes, then cool completely.

In a large mixing bowl, whisk 1 cup of heavy whipping cream with ½ cup of powdered sugar and 1 teaspoon of pure vanilla extract until soft peaks form, approximately 3-5 minutes. In another bowl, beat 1 cup of mascarpone cheese with the zest from one lemon until smooth. Fold whipped cream into mascarpone mixture.

Quickly dip each ladyfinger into the cooled lemon syrup for 1-2 seconds to moisten. Layer cookies in a trifle or baking dish, and spread half the mascarpone cream over them. Repeat with remaining ladyfingers and cream.

Cover the dish and let it chill in the fridge for at least 4-6 hours, or ideally overnight.

Garnish with extra lemon zest or candied lemon slices before serving. Slice or scoop into servings and enjoy!